Andritz Oy

Ahlstrom Machinery Oy

Andritz-ahlstrom Oy

Arto Ahvenainen

The present invention relates to a cooler ( ) for a rotary drum kiln ( ). The cooler comprises two cylindrical housings disposed one inside the other ( ), surrounding the kiln and rotating with it, which housings are mounted at the discharge end of the kiln concentrically with the kiln and between which housings an annular space ( ) is formed. The housings are attached to each other by means of longitudinal radial partition walls ( ), and the inner cylindrical housing ( ) is attached at its ends to the kiln. The annular space ( ) has a feeding inlet ( ) communicating with the kiln for leading the hot material from the kiln into the cooler and a discharge outlet for discharging the cooled material. The material to be cooled flows counter-currently in relation to the cooling gas flow. The annular space ( ) comprises at least two parts ( ) so that each of the cylindrical housings comprise at least two cylinders ( , ; , ), in the direction of the longitudinal axis of the kiln sequential, connected to each other. The cylindrical housing ( ) comprises means ( ) for attaching the cooler to the kiln essentially at the conjunction point ( ) of the sequential cylinders ( , ; , 7 ), too.

Cooler for rotary kilns

A sealing arrangement is provided between a rotary drum kiln and the stationary end thereof arranged in a material flow relation to each other, having enhanced effectiveness and requiring less maintenance. Pressurized gas, such as air, is fed to the connecting area of the drum and stationary end so that the angle &agr; between the feeding direction of the gas and a plane substantially perpendicular to the center axis of the rotary drum is 90&deg; or less (preferably between about 10-30&deg;). The air flow is directed to the seal in such a way that it prevents leaking of process gas and solid matter dust from the connecting point of the rotary drum and the feed chamber, and so that as little air as possible escapes to the surroundings. Due to the gas flow, the stationary surface and the moving surface substantially do not rub together.

Method of sealing a rotary drum connection

A method and apparatus for supplying lime sludge to a rotary kiln guides the flow of the lime sludge into the kiln, and the flow of flue gases out of the kiln, in distinct paths so that contact between the lime sludge entering the kiln and flue gases exiting the kiln is substantially prevented. This is typically accomplished by providing a general horizontal tubular duct interiorly of the kiln first end and extending into a substantially vertical flue gas conduit with an annular chamber defined between an outer surface of the tubular duct and an inner surface of an inlet to the first end of the rotary kiln. The lime sludge is introduced into the annular chamber. Spiral feeding blades are preferably provided on the outer surface of the tubular duct and the duct rotates with the rotary kiln so that the spiral feeding blades engage the lime sludge and move it toward the kiln. The lime sludge is preferably dried before it is fed into the annular chamber. Different types of baffles may be provided at a top portion of the annular chamber to cause any flue gas which enters the annular chamber to exit it, and flow into the vertical flue gas conduit, adjacent a bottom portion of the annular chamber.

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Varkaus, Finland

Arto Ahvenainen